(1) Field of the Invention
This invention generally relates to an appended underwater gun mount. More particularly, the invention relates to an appended underwater gun mount for both mounting and controlling an underwater gun so as to be able to engage and destroy attacking torpedoes.
(2) Description of the Prior Art
The current art for anti-torpedo devices is under investigation by Naval engineers in several countries who are investigating the technical and operational problems associated with torpedo defense. Efforts to defend ships and submarines against attacking torpedoes have resulted in a number of concepts for inclusion within shipboard Torpedo Defense Systems (TDS). Those concepts include sensors for detecting the sound of an incoming torpedo, development of recommended evasive maneuvers to avoid such a weapon, deployment of countermeasures to decoy the torpedo, and anti-torpedo weapons to destroy it before it strikes its intended target. Anti-torpedo weapons that are being investigated or developed include guns that are capable of firing underwater. Typically, these are medium caliber, projectile firing guns that can launch a stream of bullet-like objects at a very high velocity in rapid sequence. Such guns are envisioned as being used underwater against attacking torpedoes in a manner similar to anti-air missile systems such as the PHALANX close in weapons system (CIWS) against incoming airborne missiles.
The concept of using an underwater "machine gun" to destroy an attacking torpedo is appealing because it provides a positive and conclusive defensive response to such a situation. If the direction, or bearing, of an incoming torpedo is determined by a sensor on board a targeted vessel, requisite response action is to aim the gun and direct the release of its projectiles towards the threat. That process, however, is a complex function, composed of the combination of inter-related launcher, fire control, and operability issues that are all technically challenging. The first is the problem of providing a suitable launcher, or mounting apparatus, for containment of the gun and its ammunition. The gun mount must be capable of being controlled or moved into a position that will point the barrel of the gun towards an attacking torpedo, in accordance with an appropriate fire control solution.
Since projectiles fired from an underwater gun, or any type of conventional gun, are not controllable after release, the physical position of the gun barrel determines the direction subsequently taken by the shot. Bullets shot from guns are "unguided missiles", subject to ballistic influences such as gravity, drag, and the like, after leaving the barrel. Therefore, the gun mount must have sufficient flexibility of movement to allow the muzzle of the gun to be pointed towards any direction from which a torpedo attack is probable.
While a torpedo may strike any part of the hull of a targeted vessel, it is generally considered that the area of greatest danger from a modern torpedo is astern. One reason is that the stern of a ship, or a submarine, is the location of the screw(s) or propulsors that drive it through the water. A great deal of energy (acoustic and other) is transferred from the vessel to the surrounding medium at that location. Modern torpedoes are designed to sense and seek such energy, and thus, a homing torpedo is likely to attack from astern, unless measures have been taken, and have been successful, to eliminate that stimulus.
Another reason for expecting a torpedo attack from astern is that a common tactic for any ship, if alerted to impending danger, is to turn away from an incoming weapon. That is a natural reaction, and it is logical to minimize the relative velocity between a weapon and its target by attempting to outrun it. Also, turning away from the torpedo presents a much smaller aspect or cross section. Therefore, the ship's own maneuvers may steer the danger area, intentionally, to the stern.
Accordingly, a need in the art exists in which an anti-torpedo gun must be able to deploy a field of fire that fills a conical volume of space astern of a vessel that is host to such a defensive system. An obvious problem with respect to implementation of that capability is that the stern of a ship is the location of control and propulsion mechanisms that would be in the way of any hull mounted launcher aimed astern. Location of a gun mount aft of those mechanisms is impractical, because the stream of gunfire would issue directly into the turbulence of the ship's wake. A gun mount configured as a towed body would also be impractical, because the precise location and attitude of the module would be variable and uncertain, and deployment would be difficult. Accordingly, it is the inventor's discovery that the functional capability that is needed to engage attacking torpedoes is a hull mounted, controllable gun mount that can fire past, or around, the screws and control surfaces of the host vessel.
The following patents, for example, disclose various types of anti-torpedo devices, but do not disclose a hull mounted, controllable gun mount that can fire past, or around the screws and control surfaces of the host vessel.
U.S. Pat. No. 3,875,844 to Hicks; PA1 U.S. Pat. No. 4,215,630 to Hagelberg et al.; PA1 U.S. Pat. No. 4,855,961 to Jaffe et al; and PA1 U.S. Pat. No. 5,341,718 to Woodall, Jr. et al.
Specifically, the patent to Hicks discloses an anti-torpedo system having, in combination, a radio frequency bridge having a source of radio frequency power connected thereto, a line of reference arranged at a predetermined distance from the vessel and parallel thereto, said reference line comprising an antenna disposed beneath and in contact with the water and abeam the vessel, means for applying a radio frequency current from said source to the antenna, the ends of one of the arms of said bridge being connected to the hull of the vessel and to said antenna respectively, said one arm including an electrically conductive path through the water between the antenna and said hull, means in at least one of the other arms for initially adjusting the bridge to an off balance condition, an output circuit for said bridge, a transformer in said output circuit, detector means operatively connected to the output of said transformer, a discharge tube having the control element thereof connected to the output of said detector means, the degree of initial unbalance of said bridge being insufficient to fire said tube, a plurality of explosive missiles, a plurality of guns aimed just beneath said line of reference for firing said missiles in the direction of the torpedo, and electro-responsive firing means on each of said guns operatively connected to the plate of said tube for firing the guns when a torpedo has approached said line of reference to a point substantially subjacent with respect thereto and thereby changed the impedance of the antenna circuit and the radio frequency current flowing therein sufficiently to fire said tube.
The patent to Hagelberg et al. discloses a ship anti-torpedo system including a detecting device for detecting and locating an incoming threat, such as a torpedo, and an interrelated missile launching and control system for firing at least one warhead carrying missile into the path of the oncoming threat, the missile having an active acoustic fuse system including a highly directional sensing system for continuously monitoring the position and proximity of the incoming threat and for detonating the warhead at the optimum proximity of the incoming threat with the missile. The missile floats at a predetermined depth determined by the predetermined depth of the torpedo to be intercepted.
Jaffe et al. discloses an imaging apparatus including an array of transmitters for simultaneously transmitting more than two coded signal beams in different directions to cover different regions of a field of view, said beams being modified by objects within said field of view, signal means for providing individual coded signals to respective transmitters, at least one receiver for simultaneously receiving plural coded modified signals derived from the coded signal beams, and a processor for separating the plural coded modified signals of different codes and processing them into an image signal.
Woodall, Jr. et al. discloses an acoustic decoy round ejected by a launcher for flight above water from a sea-going vessel, the round impacting at the water surface to cause separation of a payload from a forward section of the round that is also separated from a flotation anchor tethered to the payload and fins which stabilize launched flight of the round prior to impact. The separated payload submerges from the flotation anchor at the water surface location to a tethered depth within the water from which a decoy signal is emitted.
It should be understood that the present invention would in fact enhance the functionality of the above patents by providing a hull mounted, controllable gun mount that can fire past, or around, the screws and control surfaces of the host vessel so as to be able to engage and destroy attacking torpedoes.